1. Technical Field
Example embodiments relate generally to image sensors. More particularly, embodiments of the present inventive concepts relate to a linear-logarithmic image sensors that reduce a fixed pattern noise (FPN), and electronic devices including the linear-logarithmic image sensors.
2. Description of the Related Art
An image sensor is a semiconductor device that converts a photographic image into an electric signal. Image sensors are widely used in electronic devices such as digital cameras, cellular phones, etc. Generally, an image sensor includes a linear image sensor that outputs an electric signal that is linearly proportional to incident light, a logarithmic image sensor that outputs an electric signal that is logarithmically proportional to incident light, and/or a linear-logarithmic image sensor that outputs an electric signal that is linearly proportional to weak incident light and that outputs an electric signal that is logarithmically proportional to strong incident light, etc. However, since characteristic differences exist among a plurality of unit pixels included in the image sensor, deviation may occur among respective analog signals that are output by the unit pixels in response to identical incident light. This deviation may result in a fixed pattern noise (FPN). Reducing the fixed pattern noise is important for improving the performance of an image sensor (e.g., to improve an image-quality of the image sensor).